环北部湾经济区近岸海域环境容量研究

基于无结构网格的MIKE 3D模型,建立了北部湾三维潮流水质数学模型,计算北部湾近岸海域24个主要排污口COD、无机氮和石油类的环境容量,并通过对比区域规划排污量,得出各排污区环境容量的可利用水平。计算结果表明,环北部湾近岸海域主要排污区COD、无机氮和石油类等的总海洋环境容量分别为221267.1、23 058和5 297.2 t/a,洋浦、茂名博贺等排污区由于海域开阔,水动力扩建条件好,海洋环境容量相对较大。对比各水平年的区域规划排污量,纳污海域以无机氮超载最为严重。其中,规划近期(2015年)25%排污区出现容量超载,规划远期(2020年)33%排污区出现超载。

Research on Marine Environmental Capacity in the Beibu Gulf Economic Zone

Based on the unstructured grid MIKE 3D model with the finite volume method, the 3D tidal and water quality numerical model was used to simulate the marine environmental capacity of COD, DIN and oil in the main discharge areas in the Beibu Gulf Economic Zone, China. Compared with the potential future discharges of these three types of pollutants according to the planning scenario around the Gulf, the available level of marine capacity was also discussed. The results indicated that environmental capacity of COD, DIN and oil in the Gulf were 221 267.1, 23 058 and 5 297.2 t/a, respectively. Due to the good hydrodynamic diffusing condition, the marine environmental capacities of discharge areas in Yangpu and Bohe were relatively large. The environmental capacity of DIN was seriously overloaded, which leaded to 25% and 33% of the discharge areas overloaded in 2015 and 2020, respectively.